1. Field of the Invention
The present invention relates to a system for identifying a responding station for a radio communications system, and more specifically to a responding station identification system to be incorporated in a communications system such as an amateur radio system or a CB (Citizens Band) radio system.
2. Description of Background Information
In radio communications systems such as amateur radio systems of the VHF band and the UHF band, or CB radio systems of the United States, it is general to use a single call channel and a plurality of speech channels.
Further, there is a type of communications system in which a search of an open channel, i.e., a non-busy channel of the speech channel is to be first performed and initiated by a manual operation, in the case of giving a call toward the other station(s). When a non-busy channel is found out among the speech channels, then a call to a responding station is made through the call channel so as to designate the selected speech channel. After that, both of the caller (home) station and the responding station are tuned at the designated speech channel so that a mutual communication is started.
This type of communications system, however, has a drawback that the manner of operation tends to be rather difficult. Moreover, an occupation of a speech channel is likely to occur in the communications system of this type. Therefore, it is required to eliminate the complexity of operation, so that the designation of the responding station is performed without fail. To this end, it is desirable that the identification of the responding station is executed automatically.